The round logarithmic ruler "KL - 1" is designed to perform mathematical operations of multiplication, division, squaring, taking square roots, finding trigonometric functions of sine, cosine, tangent, as well as inverse trigonometric functions, finding the area of ​​​​a circle. The set includes a passport with instructions and a box. Manufacturer: Moscow pilot plant of control devices “Kontrolpribor”. The ruler is in the original box. Secure shipping with tracking.